An electrophotographic printer includes an exposure unit having a mems scanner operable to scan a beam of light across a photoconductor. The mems scanner includes a mirror having an aspect ratio similar to the shape of the facets of a conventional rotating polygon scanner. In a preferred embodiment, the scan mirror has a length of about 750 microns in a dimension parallel to its axis of rotation and a length of about 8 millimeters in a dimension perpendicular to its axis of rotation. The mems scanner is operable to scan at a frequency of about 5 KHz and an angular displacement of about 20 degrees zero-to-peak mechanical scan angle.
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2. The mems scanner for a laser printer of
3. The mems scanner for a laser printer of
4. The mems scanner for a laser printer of
5. The mems scanner for a laser printer of
6. The mems scanner for a laser printer of
7. The mems scanner for a laser printer of
8. The mems scanner for a laser printer of
9. The mems scanner for a laser printer of
10. The mems scanner for a laser printer of
first and second opposed T-bars, each T-bar coupled to a distal point of a respective torsion arm and extending laterally in opposing directions from an axial to two equidistant lateral points therefrom; and
first, second, third, and fourth mounting pads, each mounting pad coupled to a respective equidistant lateral point of a T-bar.
11. The mems scanner for a laser printer of
12. The mems scanner for a laser printer of
13. The mems scanner for a laser printer of
14. The mems scanner for a laser printer of
15. The mems scanner for a laser printer of
16. The mems scanner for a laser printer of
17. The mems scanner for a laser printer of
a housing to which the first, second, third, and fourth mounting pads are clamped.
18. The mems scanner of
the third and fourth mounting pads are clamped directly to the housing;
the first and second mounting pads are clamped to respective first and second stacked piezo-electric actuators; and
the first and second stacked piezo-electric actuators are held in contact with the housing.
19. The mems scanner of
the first, second, third, and fourth piezo-electric actuators are held in contact with the housing.
20. The mems scanner of
21. The mems scanner for a laser printer of
22. The mems scanner for a laser printer of
23. The mems scanner for a laser printer of
24. The mems scanner for a laser printer of
25. The mems scanner for a laser printer of
26. The mems scanner for a laser printer of
27. The mems scanner for a laser printer of
28. The mems scanner for a laser printer of
29. The mems scanner for a laser printer of
a mirror formed on a surface of the silicon scan plate.
30. The mems scanner for a laser printer of
31. The mems scanner for a laser printer of
32. The mems scanner for a laser printer of
33. The mems scanner for a laser printer of
34. The mems scanner for a laser printer of
36. The electrophotographic printer of
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This application claims benefit from the U.S. Provisional Patent Application Ser. No. 60/542,896, entitled MEMS SYSTEM ADAPTED TO A LASER PRINTER, invented by Wyatt O. Davis et al., applied for on 9 Feb. 2004.
This application relates to material in the co-pending U.S. Patent Applications entitled HIGH PERFORMANCE MEMS SCANNER, invented by Wyatt O. Davis et al., application Ser. No. 10/986,640, applied for on 12 Nov. 2004; METHOD AND APPARATUS FOR MAKING A MEMS SCANNER, invented by Kelly D. Linden et al., application Ser. No. 10/986,635, applied for on 12 Nov. 2004; and METHOD AND APPARATUS FOR SCANNING A BEAM OF LIGHT, invented by Gregory T. Gibson et al., application Ser. No. 10/988,155, applied for on 12 Nov. 2004.
The present invention relates to microelectromechanical system (MEMS) scanners and particularly to their application to laser printers.
Electrophotographic, computer controlled printers have become pervasive in the office, factory, print shop, copy center, and home. An electrophotographic printer operates by transferring toner to plain paper and fusing the toner by means of heat, pressure, and/or other fixing technologies. The pattern of the transferred toner may form characters, graphic images, etc.
The term electrophotography refers to the use of modulated light, frequently a scanned laser beam, to create an electrostatic latent image on a photoconductive carrying medium such as a drum or belt. The latent electrostatic image is formed by momentary electrical conductivity of the photoconductor in response to exposure to the modulated light. The momentary conductivity allows a surface charge to discharge through the photoconductor to a conductor held at a bias voltage at locations corresponding to the modulated light exposure.
Electrophotographic printers may be made to write-white or write-black. In a write-black system, the toner charge is selected to be attracted to the photoconductor backside conductive layer bias voltage and repelled from the sensitization static charge deposited on the photoconductor surface. Thus, the spots “written” by the modulated light correspond to black areas of the printed page.
Once the electrostatic latent image is formed, the photoconductor 102 is further rotated to a developer 108, where oppositely charged toner, most often in the form of fine, dry particles, is attracted to and deposited on the surface of the photoconductor in a pattern corresponding to the latent image. The photoconductor 102 is further rotated to a transfer point, where the patterned toner is then transferred to the paper 112, often using an electrostatic attraction element 110 such as a corona wire in the form of a corotron or scorotron.
The paper 112, with toner loosely adhered thereto, is fed forward through a fusing station 114 that, generally through a combination of heat and pressure, causes the thermoplastic toner particles to permanently adhere to the paper, thus forming a robust image.
Following transfer of the toner, the photoconductive medium 102 is rotated past a discharge lamp 116 and a cleaner 118, and then repeats the process as it is rotated to the sensitizer or charger 104.
In various printers, light emitting diode (LED), liquid crystal shutter (LCS), vacuum fluorescent, and other types of arrayed light modulator write heads have been used for modulating light onto the photoconductor. Generally though, scanned laser beam exposure or imaging modules have gained favor in the art due to an appropriate balance of cost, speed, performance, and durability. An electrophotographic printer that uses a scanned laser beam to provide light modulation onto the surface of the photoconductive medium may be conveniently referred to as a laser beam printer or LBP.
One difficulty encountered with scanned laser beam exposure modules relates to the technology used to scan the laser beam. Most frequently, rotating polygon mirrors have been used. Rotating polygon mirrors may suffer from relatively large mass, slow ramp-up to speed, large size, noise, bearing reliability issues, relatively high power consumption, and other shortcomings.
Various aspects according to the disclosure relate to microelectromechanical system (MEMS) scanners and the use of a MEMS laser beam scanner in an electrophotographic printer exposure unit. Such an approach can result in reduced mass and size, faster start-up, reduced noise, higher reliability, and other advantages, compared to rotating polygon exposure units.
According to several aspects of the invention, a MEMS laser beam scanner may be formed with various physical and operational attributes; including mirror size, scan angle, scan frequency, and mirror flatness; to be especially well-adapted to an electrophotographic printer exposure unit. A MEMS mirror with extended length transverse the scanning axis can be substituted for a rotating polygon without substantial modifications to the exposure module optical design.
Other aspects will become apparent to the reader through reference to the appended brief description of the drawings, detailed description, claims, and figures.
Suspension beams 308 are coupled to scan plate 304 by respective outer (lateral) connectors 316a, 316b, 316c, 316d and respective axial connectors 318a, 318b. Taken together, suspension elements 308a, 316a, 316b, and 318a form a first suspension coupling between first torsion arm 306a and scan plate 304. Similarly suspension elements 308b, 316c, 316d, and 318b form a second suspension coupling between second torsion arm 306b and scan plate 304.
A mirror surface can be formed on the surface of scan plate 304 using metal, stacked dielectric, or other technologies known to the art. Aluminum can be used to form a mirror having greater than about 85% reflectivity at red and infrared wavelengths (having a local minimum at about 825 nanometers wavelength). Gold or silver can be used to form a mirror having greater than about 90% to 95% reflectivity at red and infrared wavelengths. Stacked (such as quarter-wave) dielectric reflectors can achieve very high reflectivity across a wide range of wavelengths.
Torsion arms 306a, 306b terminate at respective “T-bars” 312a and 312b. T-bars 312a and 312b, in turn connect to respective mounting pads 314a, 314b and 314c, 314d as illustrated. Taken together, T-bar 312a and mounting pads 314a, 314b constitute a first mounting structure for coupling torsion arm 306a to a support structure (not shown). Similarly, T-bar 312b and mounting pads 314c, 314d form a second mounting structure for coupling torsion arm 306b to a support structure (not shown). In alternative embodiments, mounting structures can take other forms, including for example a pair of rectangular mounting pads, each joined directly to a respective torsion arm, or other forms. Alternatively, a frame-type mounting structure may be formed peripheral to the scan plate 304 and torsion arms 306a, 306b. The exemplary embodiment of
When mounting pads 314a, 314b, 314c, and 314d are mounted to a housing, periodic application of power to an actuator (not shown) will cause mirror 304 to periodically rotate back and forth about the axis of rotation 310 defined by torsion arms 306a, 306b.
Scan plate 304 is formed to be approximately 8 millimeters long (in the direction perpendicular to the axis of rotation 310) and 750 micrometers wide (in the direction parallel to the axis of rotation 310). Thus, for the exemplary embodiment, the scan plate (and mirror formed thereon) has a lateral dimension about 10.67 times its longitudinal dimension.
When driven with an appropriate signal, (such as a 5 kilohertz (KHz) sine wave varying between about 0 (zero) and 25-30 volts for a four actuator design) the mirror responds with a ±20° mechanical scan angle at a frequency of 5 KHz.
As illustrated, MEMS scanner 302 includes two torsion arms 306a, 306b, each 8.76 millimeters long (including fillets), terminated on their proximal ends by a 400 micron by 200 micron elliptical fillet at respective suspensions (in particular at suspension beams 308a, 308b), and terminated on their distal ends at respective T-bars 312a, 312b, again with a 400 micron by 200 micron elliptical fillet. The torsion arms 306a, 306b are 384 microns wide. As with the rest of MEMS scanner 302, the torsion arms are etched to a full wafer thickness of 700 microns using DRIE processing. For a given scan plate mass and mass distribution, the width, depth, and length of the torsion arms and T-bars may be adjusted to produce alternative resonant scan frequencies and angles.
The suspension beams 308a, 308b are 396 microns wide, are slightly bent to make a slightly obtuse angle with respective torsion arms 306a, 306b of 91.6 degrees, and extend laterally to an extent equal to the lateral extent of the 8 millimeter lateral dimension scan plate 304. Respective suspension center connectors 318a, 318b extend from the centerlines of suspension beams 308a, 308b to the centerline of the scan plate 304, a distance of 500 microns (including fillets). The center connectors 318a, 318b are each 164 microns wide and include 100 micron radius fillets at both ends. Four suspension outer connectors 316a, 316b, 316c, and 316d extend from the ends of suspension beams 308a, 308b to the scan plate 304, one on each end of each suspension beam as indicated. The outer connectors 316a, 316b, 316c, 316d are each 250 microns wide (laterally) by 400 microns long (longitudinally) and do not have fillets. The respective suspensions thus each include a suspension beam 308, a center suspension connector 318, and two outer suspension connectors 316; and connect the torsion arms 306a, 306b to the scan plate 304 in a manner that reduces stress concentrations, spreads the torque load, and reduces dynamic deformation of the scan plate during operation. Alternative suspension configurations are possible and could be implemented by one skilled in the art.
The T-bars 312a, 312b are each 1.8 millimeters long (total lateral dimension inclusive of fillets) by 400 microns wide (longitudinal dimension) and extend symmetrically from and perpendicular to the axis formed by torsion arms 306a, 306b. The outer ends of T-bars 312a, 312b connect to four respective mounting pads 314a, 314b, 314c, 314d with 200 micron radius fillets as shown. The mounting pads are each 5 millimeters square. The geometry of the T-bars and mounting pads may be adjusted to suit application requirements.
The secondary peak at between 65 and 70 KHz corresponds to the resonant behavior of the piezo-electric stack actuators.
Curve 408 illustrates how the phase relationship of the drive signal to the MEMS scanner response inverts at the resonance points. Below 5 KHz, the phase relationship (drive to response) is 0°. Above 5 KHz but below the secondary peak, the phase relationship is −180°. At the primary resonant peak, the phase relationship inverts and passes through −90° (response lagging drive) as indicated. Above the secondary peak, the response of the system drops and the phase response again inverts, passing from −180° below the peak, through −270°(+90°) at the secondary resonance peak, to −360° (0°) at frequencies above the secondary resonance peak. To maximize efficiency, it has been found to be advantageous to operate the MEMS scanner at or very near the primary resonance peak.
For operation at 5 KHz, the resonance frequency of the MEMS scanner is trimmed to be a few hertz above 5 KHz, typically in the range of 5.001 to 5.005 KHz. Such trimming may be accomplished using methods described in U.S. Pat. No. 6,245,590, hereby incorporated by reference. It has been found to be advantageous to factory trim resonant frequency using a method of adding weight, in the form of epoxy applied to the scan plate.
To maintain contact between the MEMS scanner 302 and the piezo-electric actuator stacks 602a, 602b, respective clamps or pressure assemblies 608a and 608b (608b not shown) press the mounting pads 314a, 314b down against the actuator stacks. Clamp 608b is omitted from
The use of clamps 608 to secure the MEMS scanner 302 in housing 802 results in a mount that “floats”, allowing the mounting pads 314 to move a bit with respect to one another. In some embodiments, slight twisting of the clamps 608 during assembly can result in slight in-plane twisting of the mounting pads 314. This can result in undesirable residual stress in the T-bars and/or torsion bars of the MEMS scanner. Such twisting may be reduced or eliminated by running or “burning-in” the mounted scanner for a few hours at reduced scan angle. In an exemplary embodiment, the scanner is run at half amplitude for approximately four hours. The burn-in process can reduce the occurrence of “infant” failures associated with mechanical failure of the T-bars and/or torsion arms. Alternative, reduced twist clamp assembly designs may be substituted to reduce or eliminate the need for scanner assembly burn-in.
The MEMS scanner 302 may be driven by four piezo-electric stacks 602, one juxtaposed against each mounting pad 314a, 314b, 314c, and 314d. Alternatively, one end of the MEMS scanner may be held in a fixed position, i.e. mounting pads 314c and 314d may be clamped against a solid mounting point, and the other end of the MEMS scanner may be driven by piezo-electric actuators, i.e. mounting pads 314a and 314b may each be clamped against piezo-electric stacks as shown in
As indicated above, the MEMS scanner is trimmed to have a resonant frequency within a few hertz of the desired operational frequency. As may be appreciated from curve 402 of
The preceding overview of exemplary embodiments of the invention, brief description of the drawings, and detailed description describe exemplary embodiments of the present invention in a manner intended to foster ease of understanding by the reader. Other structures, methods, and equivalents may be within the scope of the invention. As such, the scope of the invention described herein shall be limited only by the claims.
Brown, Dean R., Koga, Yoshiro, Abe, Nobumasa, Nomura, Yujiro, Sprague, Randall B., Davis, Wyatt O.
Patent | Priority | Assignee | Title |
10114214, | Dec 25 2013 | STANLEY ELECTRIC CO , LTD | Vehicle headlight illumination apparatus having scanning laser source |
11555892, | Mar 13 2017 | Pioneer Corporation | Drive device and distance measurement apparatus |
7884525, | Aug 03 2006 | Brigham Young University; Massachusetts Institute of Technology | Carbon nanotube based compliant mechanism |
8988750, | Oct 06 2010 | Seiko Epson Corporation | Optical scanner, mirror chip, method of manufacturing optical scanner, and image forming apparatus |
9606351, | Dec 25 2013 | STANLEY ELECTRIC CO , LTD | Vehicle headlight having scanning laser source |
9876418, | Feb 08 2013 | Pioneer Corporation | Actuator |
Patent | Priority | Assignee | Title |
4530138, | Sep 30 1982 | Northrop Grumman Corporation | Method of making a transducer assembly |
5543956, | Oct 08 1992 | FUJI ELECTRIC CO , LTD | Torsional vibrators and light deflectors using the torsional vibrator |
5861979, | Jan 18 1994 | Daewoo Electronics Co., Ltd. | Array of thin film actuated mirrors having an improved optical efficiency and an increased performance |
5912608, | May 26 1995 | The Nippon Signal Co., Ltd. | Planar type electromagnetic actuator |
5969465, | Apr 01 1997 | XROS, INC | Adjusting operating characteristics of micromachined torsional oscillators |
5982528, | Jan 20 1998 | University of Washington | Optical scanner having piezoelectric drive |
6049407, | May 05 1997 | University of Washington; Washington, University of | Piezoelectric scanner |
6107115, | Dec 01 1995 | Seiko Epson Corporation | Method of manufacturing spatial light modulator and electronic device employing it |
6128122, | Mar 24 1997 | Seagate Technology LLC | Micromachined mirror with stretchable restoring force member |
6198565, | Nov 16 1998 | JVC Kenwood Corporation | Light deflection element and display apparatus using same |
6243186, | Sep 25 1996 | University of Washington | Position detection of mechanical resonant scanner mirror |
6245590, | Aug 05 1999 | Microvision Inc.; Microvision, Inc | Frequency tunable resonant scanner and method of making |
6259548, | May 28 1999 | Mitsubishi Denki Kabushiki Kaisha | Micro-mirror device |
6285485, | Jan 16 1998 | Board of Supervisors of Louisiana State University and Agricultural and | Induction microscanner |
6360035, | Jul 30 1996 | Coherent, Inc | Optical head using micro-machined elements |
6392220, | Sep 02 1998 | RPX CLEARINGHOUSE LLC | Micromachined members coupled for relative rotation by hinges |
6449079, | Dec 16 1998 | Robert Bosch GmbH | Deflectable micro-mirror |
6463085, | Sep 09 1998 | CORETEK, INC | Compact external cavity tunable lasers using hybrid integration with micromachined and electrooptic tunable elements |
6672732, | Aug 28 1999 | Robert Bosch GmbH | Micromechanical oscillating device |
6760145, | Jan 23 2003 | JDS Uniphase Corporation | Actuator for dual-axis rotation micromirror |
6769616, | Nov 22 2002 | ADVANCED NUMICRO SYSTEMS, INC | Bidirectional MEMS scanning mirror with tunable natural frequency |
6912078, | Mar 16 2001 | Corning Incorporation | Electrostatically actuated micro-electro-mechanical devices and method of manufacture |
6963679, | May 24 2000 | II-VI Incorporated; MARLOW INDUSTRIES, INC ; EPIWORKS, INC ; LIGHTSMYTH TECHNOLOGIES, INC ; KAILIGHT PHOTONICS, INC ; COADNA PHOTONICS, INC ; Optium Corporation; Finisar Corporation; II-VI OPTICAL SYSTEMS, INC ; M CUBED TECHNOLOGIES, INC ; II-VI PHOTONICS US , INC ; II-VI DELAWARE, INC; II-VI OPTOELECTRONIC DEVICES, INC ; PHOTOP TECHNOLOGIES, INC | Micro-opto-electro-mechanical switching system |
6965177, | Jun 18 2003 | Texas Instruments Incorporated | Pulse drive of resonant MEMS devices |
6999215, | Nov 08 2002 | Texas Instruments Incorporated | Multilayered oscillating functional surface |
7050211, | Nov 08 2002 | Texas Instruments Incorporated | Torsional hinged mirror assembly with central spines and perimeter ridges to reduce flexing |
7053520, | Jul 18 2003 | Regents of the University of California, The | Rotational actuator or motor based on carbon nanotubes |
7067344, | Apr 19 1999 | Murata Manufacturing Co., Ltd. | Method of manufacturing an external force detection sensor |
7123396, | Feb 05 2004 | Seiko Epson Corporation | Optical scanning apparatus and image forming apparatus |
7324751, | Oct 05 2001 | Alcatel | Selective frequency switching system and a reconfigurable optical delay circuit incorporating it |
7482730, | Feb 09 2004 | Microvision, Inc | High performance MEMS scanner |
20010048784, | |||
20010052834, | |||
20020011759, | |||
20020044276, | |||
20020122217, | |||
20020125325, | |||
20020149294, | |||
20020171901, | |||
20030016428, | |||
20030032215, | |||
20030053186, | |||
20030072066, | |||
20030122066, | |||
20030137711, | |||
20030169055, | |||
20030209073, | |||
20030214460, | |||
20030223679, | |||
20040007069, | |||
20040008400, | |||
20040060898, | |||
20040105139, | |||
20040218155, | |||
20040232107, | |||
20050018322, | |||
20050045727, | |||
20050179976, | |||
20050243396, | |||
20070211469, | |||
EP620415, | |||
EP692729, | |||
EP1197779, | |||
EP1275997, | |||
EP1338912, | |||
EP1553752, | |||
JP2000214407, | |||
JP2004069731, | |||
JP9197334, | |||
WO146741, | |||
WO3062899, |
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